<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Success</title>
</head>
<body>
    <div th:if="${#strings.isEmpty(hello)}">成功</div>
    <div th:text="${hello}">这是显示欢迎信息</div>
</body>
</html>